<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>实例</title>
</head>
<body>
    <p>不管输入是否正确，输入框都会在输入后清空。</p>
    <p>请输入5~10之间的数字：</p>
    <input id="demo" type="text">
    <button type="button" onclick="myFunction()">点我</button>
    <p id="p01"></p>
    <script>
        function myFunction(){
            var message,x;
            message=document.getElementById("p01");
            message.innerHTML="";
            x=document.getElementById("demo").value;
            try {
                if(x=="") throw "值是空的";
                if(isNaN(x))throw "值不是一个数字";
                x=Number(x);
                if(x>10) throw "太大";
                if(x<5) throw "太小";
            }
            catch(err){
                message.innerHTML="错误："+err+".";
            }
            finally{
                document.getElementById("demo").value="";
            }
        }
        </script>
        </body>
</html

>
